Compounds containing at least titanium and oxygen are known to include, for example, titanic acid compounds and titanium oxides. Titanic acids are known to include orthotitanic acid represented by the composition formula of H4TiO4 and metatitanic acid represented by H2TiO3 (Non-patent Document 1). Titanium oxides are known to include titanium dioxides having a crystal structure of rutile type, anatase type or brukite type, and also a crystal structure referred to as bronze type (Non-patent Document 2) has recently been reported.
On the other hand, since lithium secondary batteries have a high energy density and excellent cycle characteristics, they have rapidly spread recently. The lithium secondary battery is generally constituted of a positive electrode composed of a transition metal compound containing lithium, a negative electrode capable of occluding and releasing lithium, and a non-aqueous electrolyte solution. Although graphite, which can provide a flat potential, has been used as a negative electrode, since the graphite has a low discharge potential, there is apprehension regarding safety for use in large-size batteries such as for hybrid automobiles (HEV applications), and titanic acid compounds, which have a discharge potential of 1.5 V, attracts attention. For example, electrochemical characteristics of titanic acid compounds such as H2Ti6O13 and H2Ti12O25 (Non-patent Document 3) and a titanium dioxide having a crystal structure of bronze type (Non-patent Document 4) are reported.    NON-PATENT DOCUMENT 1: Encyclopaedia Chimica Editorial Board, editor, “Kagaku Daijiten (Encyclopaedia Chimica) 5 (cut-down version)”, 14th ed., published by Kyoritsu Shuppan Co., Ltd., Sep. 15, 1963, p. 872    NON-PATENT DOCUMENT 2: Thomas P. Feist, et al., “The soft Chemical Synthesis of TiO2(B) from Layered Titanates”, Journal of Solid State Chemistry 101 (1992), 275-295    NON-PATENT DOCUMENT 3: Kazuki Chiba et al., “Synthesis of a novel titanium oxide by soft chemical means, and electrochemical characteristics thereof”, Proceedings of the 74th Meeting of the Electrochemical Society of Japan, Mar. 29, 2007, Lecture No. 1H31    NON-PATENT DOCUMENT 4: Kazuki Chiba et al., “Synthesis of a layered titanium oxide by soft chemical means, and electrochemical characteristics thereof”, Proceedings of the 47th Battery Symposium, Nov. 21, 2006, Lecture No. 2P-08